This invention relates to tufting machines and more particularly to yarn handling apparatus including a yarn jerker for tufting machines.
In the production of tufted fabrics such as carpets and the like by the repeated penetration of a multiplicity of yarn carrying needles through a backing material, the needles cooperate with respective loopers or hooks to form loops in the backing material as it advances between successive needle insertions. Yarn is supplied to the needle by yarn feed mechanism at a rate which is substantially constant and which is sufficient to provide the overall yarn requirements of the needle for forming the successive loops in the backing material being tufted.
A yarn guide system is also conventionally used and this system usually comprises at least one fixed yarn guide, an adjustable stationary jerker guide, a movable jerker guide and a threader bar which takes yarn from the yarn feed mechanism and feeds it to the respective needle. Since the take-up of yarn is not constant as the needle forms a loop which is seized by the hook or looper and continues to move upwardly in readiness to begin formation of the next loop, the jerker guides function to tension the yarn and moderate variations in take-up of yarn at the needle. Conventionally, the stationary and moving jerker guides are mounted on the tufting machine frame and the needle bar respectively and are spaced apart by a relatively large distance from the needles. Additionally, the movable jerker includes an elongated upwardly inclined arm extending away from the needle bar. Thus, the jerkers occupy a significant amount of space in the tufting machine. Furthermore, and more significantly, since the moving jerker bar is attached to the needle bar, the needle bar carries a considerable offset mass, and this has a detrimental effect on the dynamic characteristics of the tufting machine.